Where's the Ring?
 

Groom can't find the rings.

I had a wedding where the Best Man hid a quarter in his hand. When he went to hand the "ring" to the bride, he dropped the quarter on the wood floor alter. It was classic.

I have done many other weddings that it was an act to hide the ring. This one is different as it was not staged nor an act. :)

I once had a couple that tried in vain to light their unity candle, but it simply didn't light! Their cussing and cursing was all caught with the wireless mic on the groom, it lasted for about a minute.